Treatment of flammable materials to impart flame resistance thereto, compositions therefor, and products thereof



Patented Jan. 22, l a V UNITED ,STATES PATENT TREATMENT. OF FLAMMABLE MATERIALS TO IMPART FLAME RESISTANCE THERE- I TO, COMPOSITIONS THEREFOR, AND PRODUCTS THEREOF Maurice Robert Burnell, Noroton Heights, and

4 2,582,961 OFFICE John Edward Lynn, Old Greenwich, Conn., assignors to American Cyanamid Company, New York, N. Y., a corporation of Maine No Drawing. Application September 17, 1949, Serial No. 116,414

Claims. (Cl. 117-436) This invention relates broadly to the treatment of flammable materials to impart flame resistance thereto, compositions therefor and products thereof. The invention is concerned more particularly with certain new'and useful improvements in the art of imparting durable flame resistance to normally flammable materials, more particularly organic textile materials, including natural cellulose-containing textiles, regenerated cellulose-containing textiles, and wooland other protein-containing textiles.

For a description of the various compounds and compositions which have been used or suggested for use as agents for treating fibrous cellulosic and other normally flammable organic materials in order to render them resistant to flame, see the book entitled Flameproofing Textile Fabrics, edited by Robert W. Little and published in 1947 by Reinhold Publishing Corporation, New York, N. Y., and the references cited therein.

Agents or treatments for imparting flame re-' sistance to normally flammable organic materials properly may be classified as (l) temporary, (2) semi-durable and (3) permanent or durable, based on their durability in providing continued resistance of the treated textile or other material to flame during use. See page 6 of the aforementioned book by Little for a more complete description of these classes. The present invention is concerned primarily with certain new and useful improvements in the permanent or durable agents or treatments of the kind aforementioned.

The durable treatments heretofore used or suggested have been of three general kinds or types:

1. Urea-phosphate type. 2. Double-bath precipitation type. 3. Metallic e hie-chlorinated body type.

See Little's book, supra, pages 179-284, for a complete description and discussion of each of these types. One of the main objections to the ureaphosphate type of treatment is the tendering effect of the treatment on the organic material whereby its tensile strength is reduced considerably. The double-bath precipitation and the metallic oxide-chlorinated body types of treatments generally yield textiles having a harsh or stiff hand, so that the treated textile has a limited field of utility.

The present invention is based on our discovery that various textile materials including natural cellulose-containing textiles, regenerated cellulose-containing textiles, and wooland other protein-containing textiles can be rendered substantially permanently resistant to flame by suitably treating them with compositions of the kind hereinafter described. Our treated textiles in thread, yarn, fabric or other form are unique in that they are characterized not only by their substantially permanent flame resistance but also by their crease and shrinkage resistance. Furthermore, these properties are obtained without excessive tendering of the textile, the treated textile in general having a total tensile strength (average of 'the sum of the tensile strength of the warp and filling) of at least of that of the untreated textile when similarly tested for tensile strength, and in some cases a tensile strength which is even higher than that of the untreated textile. Another novel feature of our invention resides in the fact that the desirable properties of flame resistance (flame retardance) crease resistance and shrinkage control of the textile are obtained in a single, one-bath treatment. Furthermore, the preferred impregnating or treating solution is aqueous and clear, and therefore has obvious practical advantages from an application standpoint.

The foregoing and other valuable and unobvious results are obtained by practicing the method of our invention. Briefly described, this method comprises impregnating the textile material to be renderedflame-resistant with an aqueous liquid composition containing the following initial or starting ingredients (that is, in the form in which they exist prior to incorporation in the aqueous liquid composition) in the specified, critical proportions by weight: 1) from 2 to 20 parts, more particularly from about 5 to 10 parts, of a heatcurable (thermosetting) reaction product of inabout 20 to 30 parts and specifically about 25 parts, of a methylol dicyandiamide, e. g., monomethylol dicyandiamide, dimethylol dicyandiamide, trimethylol dicyandiamide, etc., or a mixture in any proportions of the various methylol dicyandiamides; and (3) an oxygen-containing acid of phosphorus in an amount which is equivalent, based on phosphorus content, to from 5 to 30 parts of H3PO4. The oxygen-containing acid of phosphorus initially can be in the form (as desired or as conditions may require) of phosphoric acid (also known as orthophosphoric acid and available either as H3PO4 or as 2H3PO4.H2O), pyrophosphoric acid (H4P2O7), metaphosphoric acid (HPOa), hypophosphoric acid (H4P2Os), the various phosphorous acids, orin the form of mixtures of any or all of the various phosphorous and phosphoric acids in any proportions. or in the form of solutions (e. g., aqueous solutions, alcoholic solutions, etc.) of any one or more or all of the various phosphorous and phosphoric acids in any proportions. For example, we can use a mixture of ortho-, metaand pyrophosphoric acids, such mixed acids being sometimes colleetlvely designated as polyphosphoric" acid. The oxygen-containing acids of phosphorus are par ticularly advantageous over other acids in practicing our invention because of their excellent afterglow-retarding properties. Orthophosphoric acid is preferred.

The treating compositions of our invention are prepared, for example, by mixing together the heat-curable reaction product, e. g., trimethylol melamine, and the methylol dlcyandiamide, followed by the addition of a suitable amount of water. The mixture is stirred until the ingredients are thoroughly mixed together and the mixture is smooth. The phosphoric acid or other oxygen-containing acid of phosphorus, for instance in the form of an aqueous solution containing about 85% by weight of H3PO4, or in any other desired concentration or form, is now stirred into the smooth mixture of the other ingredients. The resulting slurry i heated, with rapid stirring, to a temperature sufficiently high, e. g., about 120 F., to cause all of the soluble ingredients to dissolve. A clear, aqueous solution usually results, especially when the preferred ingredients are employed. The mixture should be well stirred in order to prevent local polymerization of the heat-curable reaction product. Ordinarily, the mixture becomes exothermic when heated to a temperature of about 115 F. A typical formulation (I) is as follows:

Parts by weight Trimethylol melamine 5 Monomethylol dicyandiamide 25 Aqueous phosphoric acid (about 85% HSPOA) Water 55 After preparing our liquid, textile-treating composition, for instance as described above by way of example, it is preferably cooled, e. g., to about 80-90 F., and is now ready for application to the textile to be treated: Or, if desired, it may be applied hot to the textile. Lower concentrations of solids in the solution can be produced by diluting a more highly concentrated solution (e. g., a solution containing about 40 to 45% by weight of the aforementioned ingredients) with a suitable solvent, e. g., water. The bath stability of an aqueous solution containing about 40-45% by weight of the ingredients specified in Formulation I is at least 8 hours.

In some cases it may be desirable to generate the phosphoric acid or other oxygen-containing acid of phosphorus while in contact with, as in the form of a solution or admixture of, any or all of the other initial components of the treating composition. This can be done, for instance, by using (instead of the oxygen-containing acid of phosphorus per se) an equivalent amount of a suitable salt, e. g., an ammonium salt, of such an acid, and generating the free acid in situ, for example by heating or by treating the composition containing the salt with formaldehyde or a strong acid (e. g., HCl) whereby the salt is decFr'nposed and the oxygen-containing acid of phosphorus is released. If the salt is an ammonium salt, the evolved ammonia can be fixed or bound in any suitable manner, for example by adding formaldehyde in the form of paraformaldehyde or other suitable form to the composition.

Illustrative examples of textile materials that 4 can be treated with the compositions herein described to impart flame resistance thereto are those formed of or containing fibers of natural cellulose or regenerated cellulose, e. g., cotton,

linen, hemp, jute, ramie, sisal, viscose rayons, cuprammonium rayons, etc.; textiles formed of mixtures or blends of such fibrous cellulosic materials; protein-containing textiles, for instance those formed of or containing wool, silk, mohair, leather, fur, regenerated protein fibers, e. g., those produced from casein, soyabean, peanut, corn (zein) egg albumin, feathers (keratin. collagen, etc.) textiles formed of mixtures of such fibrous protein-containing materials; and textiles formed of mixtures of such fibrous protein-containing and cellulose-containing materials.

Any suitable apparatus can be employed in applying the treating composition to the textile material. For example, a dry or substantially dry textile or, if desired, a wet textile to be treated can be immersed in the aqueous composition and then passed through pressure rolls, mangles or centrifugal extractors to secure uniform impregnation and a controlled removal of the excess material. The textile in fabric or other form also can be impregnated by other methods, e. g., by spraying, brushing, etc. The wet pick-up of the composition by the textile may range, for example, between about 15% and about 300% by weight of the textile undergoing treatment. The wet pickup of the treating agent by the textile material is adjusted so that the finished textile contains from about 10% to about 100%, usually from 15 or 20% to about 40 or 45% by weight, based on the dry weight of the untreated textile, of washfast impregnant.

The amount of solids in the aqueous treating agent as applied to the textile can be varied as desired or as conditions may require, e. g., within the range of from about 5 or 10% to about '70 or 75% by weight thereof, more particularly from about 25 or 30% to about or by weight of the composition.

After. impregnating the textile material with an aqueous liquid composition, more particularly an aqueous solution, of the kind aforedescribed, the wet impregnated textile is heated to insolubilize or cure the impregnant. Heatin can be carried out in one or two steps to secure the same ultimate result. For instance, the impregnated textile can be dried at room temperature or by heating it at an elevated temperature up to 212 F. or higher. If drying is effected by heating, then as a part of the same general operation or as a separate step, the dried impregnate-d textile is heated at a temperature within the range of about 250 F. to about 400 F. The higher the temperature, the shorter is the period of heat treatment. Thus, drying the impregnated textile for 3 minutes in an oven maintained at a temperature of about 250 F. followed by heating at a higher temperature, e. g., for 10 minutes at 320 F. or for 5 minutes at 340 F., is generally effective in obtaining the desired results. These specific time and temperature periods are merely illustrative of those that can be employed.

During the drying and subsequent heat-treatment of the impregnated textile, the reactive ingredients of (1) (2) and (3) described in the sixth paragraph of this specification co-react with each other (and apparently also with the textile) to form a product of heat reaction in situ, whereby the heat-treated textile is rendered resistant to flame, creasing (wrinkling) and shrinkage.

The dried, heat-treated or cured textile usually is somewhat stiff initially, but this stiffness decreases markedly on rinsing and washing. If a flame-resistant textile. havingv a softer hand (softer feeling to the touch) is wanted, this can be attained advantageously by calendering the texiie after it has been dried and before it has been cured. If the textile is calendered after it has been cured, a loss in tensile strength generally results.

After the heat treatment at the higher temperature, that is, above the drying temperature, the cured textile is rinsed, e. g., with water, to remove free acid and any other water-soluble substances that may be present therein. A rinse of from 5 to minutes in running water at about 100 F. for rayon and woolen fabrics and at about 160 F. for cotton fabrics is usually satisfactory, and this was the practice employed in the examples which follow. The finished, rinsed and dried textile is substantially permanently resistant to flame, that is, it is resistant to flame even after numerous laundering (washing in detergent solutions) or dry-cleaning operations. Hence the flame-resistant textiles of our invention properly may be designated as being of the "durable type or kind.

In order that those skilled in the art better may understand how the present invention can be sistance was determined by a vertical flame test, using the same procedure and apparatus in all tests. The char length (charred length) was ascertained by measuring the tear length produced with a tearing weight equal to approximately 10% of the' tearing strength of the unburned fabric. The tensile strength tests were made on the rinsed samples. The flame tests were usually made on washed samples (after the stated periods) but in some cases also were made on the rinsed samples. washings were carried out in a small agitator-type washer using, unless otherwise stated, a 0.1% neutral soap solution, followed by thorough rinsing to remove any traces of soap and then drying before testing, usually (unless otherwise stated) by pressing until dry on a Hoffman steam press. The temperature of the wash water was about 160 F. in the case of the cotton fabrics and about 100 F. in the case of woolen and rayon fabrics. All percentages are by weight, as also are the parts, including those of the various formulations.

EXAMPLE 1 This example illustrates the results obtained when the flame-proofing composition described as Formulation I is used to treat various cotton, rayon and woolen fabrics.-

Table of Example 1 Vertical Flarre Test (Height of Burned .grea Sinl ltnehes) After Washing in Tsotal 'Ikfinsile oap o u ion ortreng in Kind of Textile (warp plus Filling) 1 Hr. 3 Hrs. 5 Hrs.

Tricot netting, untreated Burned completely" 39 Tricott netting, treated 3. 3. 8 3.8 27 136 x 60 broadcloth, untreated Burned completely 125 136 x 60 broadcloth, treated 3. l 3.0 3.4 112 80 x 80 cotton sheeting, untreated Burned completelya. 100 80 X 80 cotton sheeting, treated 3. 99 8 oz. woolen flannel, untreated.-. Burned completely. 68 8 oz. woolen flannel, treated 2 75 Viscose rayon, untreated..- Burned eompletel 121 Viscose rayon, treated 2. 7 100 1 In this case, the treating compcsition (Formulation I) Was diluted with Water to give a solution containing about by weight of solids.

1 After 5 Washing cycles of 10 minutes each, the treated Wool showed a shrinkage of 13% whereas the untreated wool, when similarly washed, showed a shrinkage of about 20%. Woolen flannel which has been treated with a composition like Formulation VI given under Example 6 shows a shrinkage of only 8.6% after 5 washing cycles of 10 minutes each. carried into effect, the following examples are given by way of illustration and not by way of EXAMPLE 2 This example illustrates the results obtained 1 of monomethylol dicyandiamide have been added to the diluted solutions.

Table of Example 2 Vertical Flame Test (Hei ht of Approx. Per Burned Area in Inches) After Washing in Soap Solution g i figgg d x 80 Cotton Sheeting for- I Based on the Lbs (warp Dry Wt. of the plus Filling) 10 Min. 1 Hr. 3 Hrs Untreated 0 I 100 Treated, about 40% solids in composition (A). 3. 2 3. 9 3. 9 34 l 97 Treated, about 35% solids in composition (B) 3. 3 3. 9 4. 4 30 Treated, about 30% solids in composition (0). 3. 9 3. 8 4. 7 25. 5 99 Treated, (A)+5% MMD l 2. 8 3. 7 4. 6 40 I 100 Treated, (B)+l0% MMD 2- 7 3- 3 4.1 40 104 Treated, (0) +15% MMD 3.0 3. 6 4.1 40 I 96 1 "MMD" represents monomethylol dicyandiamide. Burned completely. I

EXAMPLE 3 a cured or substantially water-insoluble state. The wet pick-up wa approximately 85% in the case of cotton textiles and approximately 100% with rayon and woolen textiles. The flame re- This example illustrates the results obtained when dicyandiamide and formaldehyde in the used in place of corresponding amounts of the said methylol compounds.

with other variations in the proportions of the heat-curable reaction product, specifically trimethylol melamine, the oxygen-containing acid of phosphorus, specifically phosphoric acid, and

5 the methylol dicyandiamide, specifically mono- Formulation n ponnumiqn 1'11 methylol dicyandiamide. For the purpose of comparison test results also are included wherein the 'lrimethylol melamine phosphoric acid or the methylol dicyandiamide 1 a di i i n 2 was omitted from the formulation. The various aqueous soln.) 4 7.6 13.2 compositions we e used in treating 80 X 80 OOH/On A ucousa ghgsglaolglc acid 0 5 0 sheeting. The per cent given for each ingre- 523i 1 1 dient refers to the weight percentage thereof in the aqueous flameprooflng composition, the re- Table of Example 3 Vertical Flame Test (Height of Burned Area in Inches) Alter Washing in Soap Total Tensile 80 x 80 Cotton Sheeting solution i gg g I plusrFilling) 10 Min. 1 Hr. 3 Hrs. 5Hrs.

Untreated 1 m0 Treated with Formulation ll 3. 0 3. 3 4. 5 4. 7 110 Treated with Formulation III 2.8 4. 7 79 l Burned completely.

From the foregoing results it will be seen that it is not essential that preformed monomethylol mainder (bringing the total to 100%) being water.

Table of Example 4 Vertical Flame Test (Height oi P C t Burned Area in Inches) er en Per Cent gg Cent Mono Phosphoric ethylol methylo Add (857 After Washing in Soap Remarks melamine Drcyandi- HPoo' Mm 80in. ror

amide musing 1 Hr. 5 Hrs.

2 25 10 3.3 4. 7 No loss in t. 5. g 10 25 10 2. 7 3.0 3.4 About 15% gain in t. s. 10 2. 9 3. 7 Treacd cotton was very 2% 25 15 8.6 3. 9 No loss in t. s.

5 25 15 2 9 3.1 3. 6 About 5% gain in t. s. 15 25 15 3.0 3.0 2. 5 About gain in t. S. 5 10 10 4. 0 7. l About 25% loss in t. s. 5 25 5 4.0 6. 4 About 5% loss in t. s.

5 25 15 2. 9 3.1 3. 4 About 57 gain in t. s. 5 25 20 2.8 3. l 3.5 About 10 a gain in t. s. 5 25 25 2. 9 3. l 3. 7 About 1% loss in t. s.

5 25 30 2. 8 2.9 4. 2 About loss in t. s. 5 35 15 3. 4 3. 1 3. 6 About 10% gain in t. s.

10 25 5 3. 7 4.1 10 25 10 2. 7 3.0 3.4 About 15% gain in t. s. 10 25 20 2. 7 2. 9

1 "t. s." means "tensile strength." I Burned completely.

'dicyandiamide or dimethylol dicyandiamide be employed, but that the ingredients and proportions thereof used in preparing said compounds likewise can be employed. However, we prefer to use monomethylol dicyandiamide (or monomethylol dicyandiamide plus added formaldehyde) or dimethylol dicyandiamide instead of dicyandiamide and formaldehye as described in the foregoing example, because of the better solubility characteristics of the methylol derivatives.

EXAMPLE 4 EXAMPLE 5 This example illustrates the results obtained 7 methylguanylurea phosphate. The various comample and heading of the tabulated data, the per;

cent given for each ingredient refers to the weight percentage thereof in the aqueous fiameprooflng composition, the remainder (bringing the total to 100%) being water. For purpose of comparison; the results obtained with an unmodified flaxne'-' proofing composition also aregiven. The total tensile strength of the untreated poplin After impregnating the test pieces, they.

The rinsed 10 Instead of a 50-50 mixture of monomethylol and dim'ethylol dicyandiamides as used in Formulation V, a mixture of these methylol derivatives in any proportions can be used, e. g., from 1 to 5 99% of th one to from 99 to 1% of the other.

'EXANIPLE 7 Y The 'same procedures and formulations are roll wed asdeseribedlunder Examples 1 to 6, incl" ve with-theexceptionpthatinstead oi trifylo melamine there is used in each case an i' amount 'of one or another of the folbimethy-lolmelamine, Tetramethylol melamine, Pentamethylol melamine,

(warp. t Y He plus filling) was 132 pounds. xam-ethylol melamine Table of E:z:ample 5 Q .voo'c'imasem (Height 5% Trimethylol Melamine Plus- I or Burned Area in Inches) Total Ten 1 I silei StIrgugth Mouomethylol Methyl- Phosphoric n Dicyandiaggg gi guanylurea Acid (85% Alter Amt Washgififl f mide, Per P E; Phosphate HSPOI), Rinsing I ing for 1 Hr.

' Cent er e Per Cent Per Cent i1 3;

25 o 15 a 9 s. 9 144 22. 5 0 12. 5 2. 8 4. 2 143 20 0 10 2. 9 4. 8 135 17. 5 0 7. 5 2. 8 148 22. 5 O 5 12. 5 2. 7 1 4. 1 148 20. 0 0 10 10 2. 7 a 3. 9 154 17. 5 0 15 7. 5 2. 7 3. 9 149 Mike 4.1 after washing for 3 hours. I 4.5 after washing for 3 hours.

EXAMPLE 6 Formulation Formulation v v v v I I I II VIII Ix 'lrimethylol melamine 5 5 5 i0 10 Monomethylol dicyandiamide. 25 12.5 25 Dimemylo melamine 5 Dimethylol dieyandiamide 25 i2. 5 2.5 Monomethylol dicymldiamide 25 25 Aqueous phosphoric acid (about Aqueous phosphoric acid (about 85% mPo.) l5 i0 85% Biro.) 15 15 15 1o 10 5 wafer 55 Water 55 55 55 55 55 The test data are given in the table which follows:

Table of Example 6 Vertical Flame Test (Height of Burned Area in Inches) Total Tensile x 80 Cotton Sheeting After Washing in Soap After a plus Filling) Rinsing 1 Hr. 3 Hrs. 5 Hrs Untreated 144 Treated with Formulation I..." 2. 6 3 0 3.4 3.8 157 Treated with Formulation IV 2.8 2 8 3.1 3.6 142 Treated with Formulation V 2.5 2 9 3.2 3. 9 149 Treated with Formulation VI... 2. 7 2.9 3. 5 143 Treated with Formulation VII 3.0 3. 3 3. 7 149 l Burned completely.

For purpose of illustration specific formula- Vertical Flame Test (Heirzht of tlons using a methylated trimethylol melamine Burned 1mm) and a methylated hexamethylol melamine, as

I well as the results of tests on 80 x 80 cotton sheet- 80 X80 mm"; XYSP,'Q 5 ing treated with the compositions, are given be- Afier Rinsing 1 Hr. 3 Hrs. 5 Hrs.

Untreated (I) Formulation Tre ted with Formulation 1U v11! 3.1 3. o 4. 7 Treated with Formulation IX. 3.1 3.0 3.1 3.8 X XI XII XIII Burned completely. Methylnicd trimethylol melamine 5 I 10 Me hyl'itcri hexamcthylol melamine 5 l0 EXAMPLE 8 Mouomclhyloldicyandiamidc 25 25 25 Aqueous phosphoric acid (about 85% The same'procedures and formulations are fol- 53 s 1 v i A n lowed as described under Examples 1 to 6,-1n-

clusive, with the exception that instead of trimethylol melamine there is used in each case an identical amount of dimethylol urea. Similar flame-resisting products are obtained but greater dimculty is encountered in applying the material because of the poorer stability of the aqueous compositions containing dimethylol urea. Hence the melamine-formaldehyde reaction products are preferred.

EXAMPLE 9 The same procedures and formulations are followed as described under Examples 1 to 6, inclusive, with the exception that instead of trimethy lol melamine there is used in each case an identical amount of a mixture of monoand dimethylol ureas, more particularly a mixture of from 1 to 25% of monomethylol urea and from 99 to 75% of dimethylol urea, specifically a 50-50 mixture of each. Results similar to those described under Example 8 are obtained.

EXAMPLE 10 The same procedures and formulations are followed as described under Examples 1 to 6, inclusive, with the exception that instead of trimethylol melamine there is used in each case a mixture of (1) a polymethylol melamine (di-,

tri-, tetra-, pentaor hexamethylol melamine, or a mixture of any or all of them) and (2) dimethylol urea, in any proportions, more particularly from 1 to 99% of the ingredient of (1) to from 99 to 1% of the ingredient of (2). Similar results are obtained.

EXAMPLE 11 The same procedures and formulations are followed as described under Examples 1 to 6, inclusive, with the exception that instead of trimethylol melamine there is used in each case an identical amount of one or another of the following alkyl (specifically methyl) ethers of polymethylol melamines Methyl ether of dimethylol melamine, Methyl ether of trimethylol melamine, Methyl ether of tetramethylol melamine, Methyl ether of pentamethylol melamine, Methyl ether of hexamethylol melamine,

Vertical Flame Test (Height 0! Burned Area in Inches) x 80 Cotton Sheeting Alter Washing in Soap After Solution for- Rinsing 1 Hr. 3 Hrs. 5 Hrs.

Untreated Treated with Formulation X 3.0 3.3 3.4 i. 7 Treated with Formulation XI 3.2 3. 4 3. 4 3. 7 Treated with Formulation XII. 2.8 3.1 3. i 4. 5 Trent ed with Formulation XIII 2. 9 3. l 3. 6 3. 5

1 Burned completely.

Instead of the ethers of methylol melamines mentioned under this example, we can use a mixture of any or all of the said ethers in any proportions with any one or more, or all, of the following:

Dimethylol urea,

Dimethyl ether of dimethylol urea, Dimethylol melamine, Trimethylol melamine, Tetramethylol melamine, Pentamethylol melamine, or Hexamethylol melamine.

Similar results are obtained.

It will be understood, of course, by those skilled in the art that in the foregoing and other examples herein where reference is made to a urea or melamine derivative, more particularly to a methylol urea or a methylol melamine, it is not necessary to use a pure compound or mixture of pure compounds. Instead we can use such compounds or mixtures thereof as commercially produced or reaction products of formaldehyde and urea and/or melamine wherein the reaction has proceeded somewhat beyond the methylol stage so that resinification to some extent has occurred. However, it is usually desirable to employ such reaction products while they are still in essentially a water-soluble (or readily waterdispersible) or a phosphoric acid-soluble stage.

EXAMPLE 12 The'same procedures and formulations are followed as described under Examples 1 to 6, inclusive, with the exception that instead of trimethylol melamine there is used in each case an identical amount of a dialkyl (specifically dimethyl) ether of dimethylol urea. Similar results are obtained.

EXAMPLE 13 The same procedures and formulations are followed as described under Examples 1 to 6, in- TomTensfle Sm thin Lb elusive, with the exception that instead of tri- (warp plus Fifuug) methylol melamine there is used in each case an identical amount Of a mixture Of (1) the mono- Mercerized y u Afterwflshmgin s methyl ether of monomethylol urea and (2) the' Mm Solution fordimethyl ether of dimethylol urea, more particu- Rinsing larly a mixture of from 1 to 25% of the monom 5Hrs. 101m. methyl ether of (1) and-from 99 to 75% of the dimethyl ether of (2), specifically a 50-50 mix- Untreated-1 48 47 43 T r d th F ul t I. ture of each. Similar results are obtained. X 3 S;11ds' f f'f 2 35 41 Treate wit Formulation 1, EXAMPLE 14 about solids 41 42 39 15 Treated with Formulation VI,

This example illustrates the properties of mer- 95235 a'zb ig- 0 1 cerized voile before and after treatment with about f ff 44 42 38 flameprooflng compositions of our invention. The treated voile possessed good resistance to flame.

Table A of Example 14 Table 0 of Example 14 Gurley Stiflness in Mg. Warp Shrinkage in Per Cent after; Washing in Soap Solu- 011 01'".- g oo ed voile g washing in Moroerlzed Voile 0 ution for- Bin-sing 1 Hi. 2 HIS. 3 HIS.

5 Hrs. 10 Hrs. I

Untreated 2. 8 3. 6 3. 9 Treated with Formulation I, about Untreated 5.9 2.9 2.8 35% solids 0.8 1.1 1.1

Treated with Formulation I (see Treated with Formulation I, about Ex. 6).8b9l.lt 35% solids} 127.8 32.6 20.8 10% solids 0.8 1.1 1.4 Treated wi h Formula ion I. reated with Formulation VI,

about 10% Solids 15.9 6. 5 4.6 about solids 0.6 0.8 0. 8 T ittedw Formulation VI (506 Treated with Formu ation Vl,

Ex. 12, about 35% solids 147.0 78.5 55.9 about10% solids 0.8 0.8 1.1 Treate with Formulation VI,

about 10% solids 21. 2 8. 5 6. 8

' 35 The apparatus and method employed in making this test are EXAIVIPLE 15 described. for example, in Bulletin N0. 1600 published by W. & L. E. Gurley. Troy, N. Y.

1 The composition was diluted with water before use to give a solution containing about 35% by weight of solids.

The composition was diluted with water before use to give a solution containing about 10% by weight of solids.

Table B of Example 14 This example illustrates the results of treating mercerized voile with Formulations I and VI (see Example 6) without diluting it with water 40 to a lower concentration of solids.

Table of Example 15 Total T B. L Vertical Flame Total Tensile Taber Abrasion fi Jarret. Lei-ts; i a it (s a u e l r p us ness n g. um r o Stated Period. in Inches) Filling) ggig g Cycles) MERCERIZED VOILE, UNTREATED Rinsed Burned com- 49 2. 7 4. 2 632 pletely. Washed 1 hr ..d0 40 2. 8 4.4 588 Washed 3 hrs. .d 46 2. 7 4. 3 643 Washed 5 hrs d 47 2. 8 4. 2 692 TREATED WITH FORMULATION I Rinsed 3. 0 54 4. 9 492 Washed 1 hr.. 3. 2 51 17 4. 8 582 Washed 3 hrs.-.. 3. 5 47 i2 4. 8 386 Washed 5 hrs 4. 7 44 8 5. 0 630 TREATED WITH FORMULATION VI Rinsed 3. 4 59 4. 5 1072 Washed 1 hr. 3.3 56 81 3. 9 1115 Washed 3 hrs. 3. 4 53 46 4. 6 591 Washed 5 hrs 3. 8 43 34 4. 2 640 The phosphorous acid was used in the form of {2.50% aqueous solution, and the amount of water specified in Formulation XV includes that which is present in the phosphorous acid.

The above compositions were used in treating Total T. B. L. Vertical Flame Total Tensile Taber Abrasion g 32 383 2 Test (Height Strength in Gurley Stiiligffgifgiif Res stance g or Burned Area Lbs. (Warp plus ness in Mg. (warn i (Number of c in Inches) Filling) Fming) Cycles) M'E RCERIZED POPLIN, UNTREATED Rinsed Burned com- 144 15 3. 9 1522 pleteiy. Washed 1 hr. l6 4. 2 1692 Washed 3 hl'S. l7 3. 8 1639 Washed 5 hrs 18 4. 1654 N I, UNCALENDERED Rinsed 2. 7 139 256 5. 8 $39 Washed 1 hl' 3. 2 137 57 5. 2 1752 Washed 3 hrs. 3. 1 129 43 5. 3 1918 Washed hrs 4. 1 I28 31 5. I 1331 TREATED WITH FORMULATION I, COLD CALENDERED 2. 9 I26 66 5. 4 1637 3. 1 98 56 5. 3 1308 3. 4 91 32 5. 5 1538 Washed 5 hrs 4. 5 90 29 5. 2 1387 TREATED WITH FORMULATION v1, UNCALENDERED Rinsed 2. 9 145 345 5. 4 3672 Washed 1 hi.. 3. 3 132 194 5. 4 3090 washed 3 hrs. 3. 2 135 93 5. 6 2954 Washed 5 hrs 3. 7 124 72 5. 6 2217 TREATED WITH FORMULATION VI, COLD CALENDERED 2. 9 127 115 5. 6 1964 3. 4 99 GO 5. 9 1379 3. 4 107 47 6. 0 2592 Washed 5 hrs 4. 0 102 44 5. 5 2052 In the table of Example 16, it will be noted from the results of Gurley stiffness tests on the 80 x 80 cotton sheeting. The results were as follows:

Table of Example 17 I Burned completely.

rinsed, calendered and uncalendered samples that oalendering causes a marked reduction in the stiffness of the treated, rinsed samples.

EXAMPLE 17 This example illustrates the use of flameproofing compositions of our invention in which oxygen-containing acids of phosphorus other than phosphoric (orthophosphoric) acid are employed. The formulations were as follows:

Formulation XIV XV 'Irimethyioi melamine I 5 5 Monomethgioi dicyandiamide 25 Pyrophosp oric acid (100%) l5 Phosphorous (orthophosphorous) ac l5 Wate 55 The proportions of heat-curable reaction product (numerous illustrations of which are given in the various examples). methylol dicyandiamide and oxygen-containing acid of phosphorus, more particularly a phosphoric acid (e. g.,

' HaPOi) are critical in producing a durable flameresistant textile that will satisfy the requirements of the trade. The specified minimum amount of the acid of phosphorus is required in order to obtain adequate flame resistance and retardance of afterglow. On the other hand, it HaPOi or other oxygen-containing acid of phosphorus is used much in excess of the maximum amount specified, then excessive tendering (loss in tensile strength) of the textile occurs. The methylol dicyandiamide and heat-curable melamine-formaldehyde, urea-formaldehyde or melamine-ureaformaldehyde reactionproduct should be used other ingredients and the conditions are the same, an increase in the content of heat-curable (thermosetting or potentially thermosetting) nitrogenous reaction product increases the durability; stiffness and tensile strength of the treated textile. (The heat-curable nitrogenous reaction product initially may be either resinous or potentially resinous, and initially may be normally crystalline but convertible, e. g., under heat, to a resin.) Ordinarily, too (when proportions of other ingredients and conditions are the same), increasing the content of mythylol dicyandiamide increases the durability and tensile strength of the treated textile as well as the effectiveness of the treatment. The nitrogen contents of the heat-curable nitrogenous reaction product and of the methylol dicyandiamide also add to the flame resistance of the treated textile, especially in view of the proportions thereof to the oxygen-containing acid of phosphorus, specifically phosphoric acid. An optimum nitrogen-to-phosphorus ratio in the additives generally provides optimum flame resistance when other conditions are the same, but in some cases is may be desirable to sacrifice maximum flame resistance in order to improve other useful properties of the treated textile, e. g., crease resistance, shrinkage resistance, durability, tensile strength, etc.

The fundamental treating compositions of this invention can be modified by incorporating therein various soluble or dispersible modifying agents which aid in further improving the flameresistant characteristics of the treated material or which facilitate the technique of application. For instance, the compositions can also contain minor amounts (e. g., from 1 to 30% by weight of the total solids content) of such glow retardants as the glow-retarding borates, phosphates, pyrophosphates, etc., e. g., zinc borate, zinc phosphate, zinc ammonium phosphate, stannic phosphate, phenyl diamido phosphate. melamine pyrophosphate, etc. wAgents which have a buffering effect on the composition after being applied to the fabric or other textile, e. g., calcium carbonate, magnesium oxide, hexamethylene tetramine and other polyalkylen'e polyamines, etc., can be incorporated into the treating compositions as desired or as conditions may require. Examples of other dispersible additives are metallic oxides, e. g., zirconium, tin, titanium, antimony and bismuth oxides; and thermally unstable, halogen-containing thermoplastic substances, more particularly such substances containing at least 20% of combined halogen and capable of rupturing under heat, at carbon-halo.- gen bonds, including halogen-containing vinyl resins in which not less than 20% by weight of combined halogen is present, for instance polymeric-and copolymeric .vinyl chloride and others such as are mentioned in Loukomsky et al. copending application Serial No. 64,416, flled December 9, 1948, now Patent No. 2,519,388, issued August 22, 1950. The amounts of such oxides and halogen-containing thermoplastic substances in the compositions and their ratio to each other can be the same as are given in the said Loukomsky et al. application.

The present invention is applicable to the production of a wide variety of flame-resistant materials. e. g., wearing apparel of all kinds. especially-childrens clothes and clothing used by the armed forces, curtains, draperies, sheeting, furniture coverings, linings for electric blankets, net fabrics, non-woven fabrics, chenilles, etc., and which are made of materials such as are described in the first paragraph of this specification and elsewhere herein. Other applications of the flame-resistant products of our invention include those described in chapters VII and VIII of the aforementioned book, edited by Little, entitled Flameproofing Textile Fabrics. The compositions of this invention also are useful in the treatment of wood (in veneer or other form) as well as in rendering flame resistant other cellulosic and other normally flammable materials which are not in textile form.

The terms flame resistance and flame-re sistant" as used herein and in the appended claims with reference to textile materials are used generically to include within their meanings treated materials (e. g., treated fabrics) which, after ignition, will continue to burn at a relatively slow rate as well as those which, after ignition, will burn over only a limited area beyond that directly exposed to the source of ignition and which may be specifically designated as fire-resistant materials. It will be apparent from the examples herein given that most of the products of our invention properly fall within the specific classification of fire-resistant materials.

The terms textile" and textile material" as used generically herein and in the appended claims include within their meanings filaments, fibers, rovings, slivers, threads, yarns, twisted yarns, etc., as such or in woven, felted or otherwise formed fabrics, sheets, cloths and the like.

We claim:

1. A composition adapted for use in the treatment of natural cellulosic and other textile materials to impart flame resistance thereto, said composition comprising an aqueous treating agent containing the following initial ingredients in the specified proportions by weight: (1) from 2 to 20 parts of a heat-curable member of the class consisting of methylol melamines, methylated methylol melamines, methylol ureas, methylated methylol ureas, mixtures thereof, and water-soluble reaction products and phosphoric acid-soluble reaction products of the said methylol compounds and of mixtures of the said methylol compounds; (2) from .10 to 35 parts of a methylol dicyandiamide; and (3) an oxygencontaining acid of phosphorus in an amount which is equivalent, based on phosphorus content, to from 5 to 30 parts of H3PO4- 2. A composition as in claim 1 wherein the heat-curable substance of (1) is a polymethylol melamine, and the oxygen-containing acid of phosphorus of (3) is phosphoric acid in the stated amount.

3. A composition as in claim 1 wherein the methylol dicyancliamide of (2) is monomethylol dicyandiamide, and the oxygen-containing acid of phosphorus of (3) is phosporic acid in the stated amount.

4. A composition adapted for use in the treatment of natural cellulosic and other textile materials to impart. flame resistance thereto, said composition comprising an aqueous solution containing the following initial ingredients in the specified proportions by weight: (1) from about 5 to 10 parts of a polymethylol melamine; (2)- about 20 to 30 parts of monomethylol dic'yandil9 amide; and (3) phosphoric acid in an amount corresponding to from about 10 to 15 parts of 85% H3PO4.

5. A composition as in claim 4 whereinthe reaction product of 1) is trimethylol melamine.

6. The method which comprises impregnating a textile material to be rendered flame-resistant with an aqueous composition containing the following initial ingredients in the specified proportions by weight: (1) from 2 to 20 parts of a heat-curable member of the class consisting of methylol melamines, methylated methylol melamines, methylol ureas, methylated methylol ureas, mixtures thereof. and water-soluble reaction products and phosphoric acid-soluble reaction products of the said methylol compounds and of mixtures of the said methylol compounds; (2) from 10 to 35 partsof a methylol dicyandiamide; and (3) an oxygen-containing acid of phosphorus in an amount which is equivalent, based on phosphorus content, to from 5 to 30 parts of 85% :HJPOA; drying the impregnated textile followed by heating the dried textile at a temperature within the range of about 250 F. to about 400 F.; and removing any residual watersoluble substances from the resulting textile.

7. A method as in claim 6 wherein the aqueous composition contains the following initial ingredients in the specified proportions by weight: (1) from about 5 to 10 parts of a polymethylol melamine; (2) about 20 to 30 parts of monomethylol dicyandiamide; and (3) phosphoric acid in an amount corresponding to from about 10 to parts of 85% HaPOi.

8. A method as in claim 6 wherein the textile material which is rendered flame-resistant is a natural cellulose-containing textile.

9. A method as in claim 6 wherein the textile material which is rendered flame-resistant is a wool-containing textile.

l0. Flame-resistant textile materials which are normally flammable textile materials impregnated and rendered flame-resistant with the product of heat reaction in situ of a mixture including the following initial ingredients in the specified proportions by weight: (1) from 2 to parts of a heat-curable member of the class consisting of methylol melamines, methylated methylol melamines, methylol ureas, methylated methylol ureas, mixtures thereof, and watersoluble reaction products and phosphoric acidsoluble reaction products of the said methylol compounds and of mixtures of the said methylol compounds; (2) from 10 to 35 parts of a methylol dicyandiamide; and (3) an oxygen-containing acid of phosphorus in an amount which is equivalent, based on phosphorus content, to from 5 to 30 parts of HJPO4.

ll. Flame-resistant textile materials as in claim. 10 wherein the heat-curable substance of (1) is a polymethylol melamine, and the oxygencontalning acid of phosphorus of (3) is phosphoric acid in the stated amount.

12. Flame-resistant textile materials as in claim 10 wherein the methylol dicyandiamide of (2) is monomethylol dicyandiamide, and the.

oxygen-containing acid of phosphorus of (3) is phosphoric acid in the stated amount.

13. Flame-resistant textile materials as in claim 10 wherein the methylol dicyandiamide of (2) is dimethylol dicyandiamide, and the oxygencontaining acid of phosphorus of (3) is phosphoric acid in the stated amount.

14. Flame-resistant cotton cloth which is impregnated with the product of heat reaction in situ of a mixture including the following initial ingredients in the specified proportions by weight: (1) from about 5 to 10 parts of polymethylol melamine; (2) about 25 parts of monomethylol dicyandiamide; and (3) phosphoric acid in an amount corresponding to from about 10 to 15 parts of 85% HaPO4.

15. Flame-resistant wool-containing fabric material which is impregnated with the product of heat reaction in situ of a mixture including the following initial ingredients in the specified proportions by weight: (1) from about 5 to 10 parts of a polymethylol melamine; (2) about 25 parts of monomethylol dicyandiamide; and (3) phosphoric acid in an amount corresponding to from about 10 to 15 parts of 85% HIiPO i.

MAURICE ROBERT BURNELL. JOHN EDWARD LYNN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,191,362 Widmer et a1. Feb. 20, 1940 2,409,906 Scott Oct. 22, 1946 2,488,034 Pingree et al. Nov. 15, 1949 FOREIGN PATENTS Number Country Date 476,043 Great Britain Nov. 29, 1937 196,034 Switzerland May 16, 1938 

6. THE METHOD WHICH COMPRISES IMPREGNATING A TEXTILE MATERIAL TO BE RENDERED FLAME-RESISTANT WITH AN AQUEOUS COMPOSITION CONTAINING THE FOLLOWING INITIAL INGREDIENTS IN THE SPECIFIED PROPORTIONS BY WEIGHT: (1) FROM 2 TO 20 PARTS OF A HEAT-CURABLE MEMBER OF THE CLASS CONSISTING OF METHYLOL, MELAMINES, METHYLATED METHYLOL MELAMINES, METHYLOL UREAS, METHYLATED METHYLOL UREAS, MIXTURES THEREOF, AND WATER-SOLUBLE REACTION PRODUCTS AND PHOSPHORIC ACID-SOLUBLE REACTION PRODUCTS OF THE SAID METHYLOL COMPOUNDS AND OF MIXTURES OF THE SAID METHYLOL COMPOUNDS; (2) FROM 10 TO 35 PARTS OF A METHYLOL DICYANDIAMIDE; AND (3) AN OXYGEN-CONTAINING ACID OF PHOSPHORUS IN AN AMOUNT WHICH IS EQUIVALENT, BASED ON PHOSPHORUS CONTENT, TO FROM 5 TO 30 PARTS OF 85% H3PO4; DRYING THE IMPREGNATED TEXTILE FOLLOWED BY HEATING THE DRIED TEXTILE AT A TEMPERATURE WITHIN THE RANGE OF ABOUT 250* F. TO ABOUT 400* F.; AND REMOVING ANY RESIDUAL WATERSOLUBLE SUBSTANCES FROM THE RESULTING TEXTILE. 